TW201947694A - Micro LED adsorption body - Google Patents

Abstract

The present invention relates to a micro LED adsorption body for vacuum-sucking micro LEDs. More particularly, the present invention relates to a micro LED adsorption body provided with a mask below a porous member to increase vacuum pressure for vacuum-sucking micro LEDs such that the micro LEDs are transferred without deviation.

Description

Micro LED adsorbent

The invention relates to an adsorbent that adsorbs a light emitting diode (LED).

Currently, the liquid crystal display (LCD) device is still the mainstream in the display market, but Organic Light Emitting Diode (OLED) is rapidly replacing LCD and gradually becoming the mainstream. Recently, when display companies' participation in the OLED market has become a boom, Micro LED (hereinafter referred to as "micro LED") displays have gradually become the next-generation displays. The core raw materials of LCD and OLED are liquid crystal and organic materials. In contrast, micro LED displays are displays that use LED chips in units of 1 to 100 micrometers (μm) as the light-emitting materials.

As Cree applied for a patent on "Micro-Light Emitting Diode Arrays for Increasing Light Output" in 1999 (Registered Patent Gazette Registration No. 0731673) and the term micro LED appeared, related studies have been published successively Thesis, and research and development. As a problem to be solved in order to apply micro LEDs to displays, it is necessary to develop a custom microchip based on flexible raw materials / components for manufacturing micro LED components, and a micron-sized LED chip transfer technology is required. With the technology of accurately mounting (Mounting) the pixel electrode of the display.

In particular, regarding transfer of transferring micro LED elements to a display substrate, conventional LED pick and place equipment cannot be used because the size of LEDs has been reduced to units of 1 to 100 micrometers (μm). High-precision transfer head technology. Regarding this transfer head technology, several configurations described below are disclosed, but each technology disclosed has several disadvantages.

The Luxvue company in the United States has disclosed a method for transferring micro LEDs using an electrostatic head (Publication Gazette Publication No. 2014-0112486, hereinafter referred to as "Existing Invention 1"). The transfer principle of the existing invention 1 is to apply a voltage to a head portion made of a silicon material, thereby generating a close contact with the micro LED due to an electrostatic phenomenon. In the method, when the electrostatic induction is performed, the micro LED damage caused by the electrostatic phenomenon is caused by the voltage applied to the head.

X-Celeprint Corporation in the United States has disclosed a method for transferring a micro LED on a wafer to a desired substrate by using a polymer material having elasticity as a transfer head (Publication Publication No. 2017-0019415, hereinafter referred to as " Existing Invention 2 "). Compared with the electrostatic head method, the method does not have the problem of LED damage, but has the following disadvantages: during the transfer process, only the adhesive force of the elastic transfer head is greater than the adhesive force of the target substrate can the micro LED be stably transferred, which needs to be performed separately. The process used to form the electrode. In addition, it is also very important to maintain the adhesion of the elastic polymer substance continuously.

The Korea Institute of Optical Technology has disclosed a method for transferring micro LEDs by using cilia and then constructing a head (registered patent publication registration number 1754528, hereinafter referred to as "existing invention 3"). However, the conventional invention 3 has a disadvantage that it is difficult to produce a bonding structure of cilia.

The Korea Institute of Machinery has disclosed a method for transferring micro LEDs by applying an adhesive on a roller (registered patent publication registration number 1757404, hereinafter referred to as "existing invention 4"). However, the conventional invention 4 has the following disadvantages: the adhesive needs to be continuously used, and the micro LED is also damaged when the roller is pressurized.

Samsung Display has disclosed a method for transferring a micro LED to an array substrate through electrostatic induction by applying a negative voltage to the first and second electrodes of the array substrate while the array substrate is immersed in a solution (Publication Patent Publication No. 10-2017 -0026959, hereinafter referred to as "Existing Invention 5"). However, the conventional invention 5 has the following disadvantages: in terms of immersing the micro LED in a solution and transferring it to the array substrate, an additional solution is required, and thereafter a drying process is required.

LG Electronics has disclosed a method of arranging a head holder between a plurality of pickup heads and a substrate and deforming the shape as the plurality of pickup heads move to provide freedom to the plurality of pickup heads (Publication Publication No. 10-2017- No. 0024906, hereinafter referred to as "Existing Invention 6"). However, the conventional invention 6 has a disadvantage in that it is a method for transferring micro LEDs by applying a bonding substance having a bonding force to the bonding surfaces of a plurality of pick-up heads, and therefore requires a separate process for coating the pick-up head with a bonding substance.

In order to solve the problems of the existing inventions described above, the above-mentioned disadvantages need to be improved while directly using the basic principles adopted by the existing inventions, but the disadvantages described above are derived from the basic principles used in the existing inventions, so the basic principles are maintained There are limits to the aspects that can improve the disadvantages at the same time. Therefore, the applicant of the present invention not only improves these shortcomings of the prior art, but also reveals a novel way that has not been considered in the existing invention.

[ Prior art literature ]

[ Patent Literature ]
(Patent Document 1) Registered Patent Gazette Registration No. 0731673 (Patent Document 2) Published Patent Gazette Publication No. 2014-0112486 (Patent Document 3) Published Patent Gazette Publication No. 2017-0019415 (Patent Document 4) Registered Patent Gazette Registration Number 1754528 (Patent Document 5) Registered Patent Gazette Registration Number 1757404 (Patent Document 6) Published Patent Gazette 10-2017-0026959 (Patent Document 7) Published Patent Gazette 10-2017-0024906

[ Problems to be solved by invention ]

Therefore, an object of the present invention is to solve the problem of the micro LED adsorbent disclosed so far and provide a mask provided on the lower part of the porous member, thereby forming a large vacuum pressure and changing the adsorption force when the micro LED is vacuum adsorbed. It is a micro LED absorber that is high and can be transferred without dropping the micro LED.

[ Problem solving ]

A micro LED adsorbent according to a feature of the present invention is provided with a porous member having air holes, and a mask provided to a lower portion of the porous member and having an opening portion.

In addition, the micro LED adsorbent is characterized in that the mask is made of nickel steel.

In addition, the micro LED adsorbent is characterized in that the mask is made of a metal material.

In addition, the micro LED adsorbent is characterized in that the mask is made of a film material.

In addition, the micro LED adsorbent is characterized in that the mask is made of paper.

In addition, the micro LED adsorbent is characterized in that the mask is provided by being adsorbed to the porous member by a vacuum suction force of the porous member.

[ Invention effect ]

As described above, the microLED adsorbent of the present invention is equipped with a mask, and the vacuum pressure of the vacuum-adsorbed microLED can be formed more through the opening of the mask. Therefore, the microLED is vacuum-adsorbed to a porous member having a uniform flatness. In the lower surface, the vacuum suction function can be performed more fully, which can prevent falling off during vacuum suction.

The following merely illustrates the principles of the invention. Therefore, although not explicitly described or illustrated in this specification, those skilled in the art can implement the principles of the invention and invent various devices included in the concept and scope of the invention. In addition, it should be understood that all the conditional terms and examples listed in the present specification are only used to understand the concept of the invention explicitly in principle, and are not limited to the examples and states specifically listed as such.

The above-mentioned objects, features, and advantages will become clearer from the following detailed description in relation to the accompanying drawings. Therefore, those skilled in the art to which the invention pertains can easily implement the technical idea of the invention.

The embodiments described in this specification will be described with reference to a cross-sectional view and / or a perspective view which are ideal illustrations of the present invention. In order to effectively explain the technical contents, the thicknesses of the films and regions shown in these drawings, the diameter of the holes, and the like are exaggeratedly illustrated. The form of the illustration is deformed by manufacturing techniques and / or tolerances. In addition, the number of micro LEDs shown in the drawings is only a part of the drawings. Therefore, the embodiments of the present invention also include changes in the forms that occur according to the manufacturing process, and are not limited to the specific forms shown.

When describing various embodiments, even if the embodiments are different, for the sake of convenience, the constituent elements that perform the same functions are given the same names and the same reference signs. In addition, for convenience, the configurations and operations described in the other embodiments are omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating a plurality of micro LEDs 100 that are a transfer object of a micro LED adsorbent according to a preferred embodiment of the present invention. The micro LED 100 is fabricated and positioned on the growth substrate 101.

The growth substrate 101 may include a conductive substrate or an insulating substrate. For example, the growth substrate 101 may be formed of at least any one of sapphire, SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ O ₃ .

The micro LED 100 may include a first semiconductor layer 102, a second semiconductor layer 104, an active layer 103 formed between the first semiconductor layer 102 and the second semiconductor layer 104, a first contact electrode 106, and a second contact electrode 107.

The first semiconductor layer 102, the active layer 103, and the second semiconductor layer 104 may use a metal organic chemical deposition method (MOCVD), a chemical deposition method (CVD), or a plasma chemical deposition method (PECVD). , Plasma-Enhanced Chemical Vapor Deposition), Molecular Beam Epitaxy (MBE, Molecular Beam Epitaxy), HVPE (Hydride Vapor Phase Epitaxy) and other methods.

The first semiconductor layer 102 may be implemented by, for example, a p-type semiconductor layer. selected from p-type semiconductor layer has _{In x Al y Ga 1 - x} - y N (0≤x≤1,0≤y≤1,0≤x + y≤1) semiconductor material composition formula, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. can be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

The second semiconductor layer 104 may be formed including, for example, an n-type semiconductor layer. The n-type semiconductor layer may be selected from a semiconductor material having a composition formula of In _x Al _y Ga _{1 - x - y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. can be doped with n-type dopants such as Si, Ge, Sn.

However, the present invention is not limited thereto, and the first semiconductor layer 102 may include an n-type semiconductor layer, and the second semiconductor layer 104 may include a p-type semiconductor layer.

The active layer 103 is a region where electrons and holes are recombined, and the electrons and holes are recombined to transform into a low energy level, thereby generating light having a wavelength corresponding thereto. The active layer 103 may include, for example, a semiconductor material having a composition formula of In _x Al _y Ga _{1 - x - y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1), and may be formed of a single quantum well Structure or Multi Quantum Well (MQW). In addition, a quantum wire structure or a quantum dot structure may be included.

A first contact electrode 106 may be formed on the first semiconductor layer 102 and a second contact electrode 107 may be formed on the second semiconductor layer 104. The first contact electrode 106 and / or the second contact electrode 107 may include one or more layers, and may be formed of various conductive materials including metals, conductive oxides, and conductive polymers.

A plurality of micro LEDs 100 formed on the growth substrate 101 can be cut along a cutting line using a laser or the like, or separated into a single by an etching process, and a plurality of micro LEDs 100 can be separated from the growth substrate 101 by a laser peeling process.

In FIG. 1, “P” refers to the distance between the micro LEDs 100, “S” refers to the separation distance between the micro LEDs 100, and “W” refers to the width of the micro LEDs 100.

FIG. 2 is a diagram illustrating a microLED structure formed by transferring a microLED adsorbent according to a preferred embodiment of the present invention to a display substrate for installation.

The display substrate 301 may include various raw materials. For example, the display substrate 301 may include a transparent glass material mainly composed of SiO ₂ . However, the display substrate 301 is not necessarily limited to this, and may be formed of a transparent plastic material to have usability. The plastic material may be selected from the group consisting of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI, polyetherimide), and polyethylene naphthalate (PEN, polyethylene naphthalate), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polyimide, and polycarbonate (PC ), Organic triacetate (TAC), cellulose acetate propionate (CAP).

In the case of a back-emitting type in which an image is directed toward the display substrate 301, the display substrate 301 needs to be formed of a transparent material. However, in the case of a front-emission type in which an image is realized in a direction opposite to the display substrate 301, the display substrate 301 does not have to be formed of a transparent material. In this case, the display substrate 301 may be formed of a metal.

In the case where the display substrate 301 is formed of a metal, the display substrate 301 may include a material selected from the group consisting of iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), nickel steel (Invar) alloy, Inconel alloy, and One or more ethnic groups made up of Kovar alloys are not limited thereto.

The display substrate 301 may include a buffer layer 311. The buffer layer 311 can provide a flat surface and can block foreign matter or moisture from penetrating. For example, the buffer layer 311 may contain an inorganic substance such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide, or titanium nitride, or an organic substance such as polyimide, polyester, or acrylic acid. A laminated body composed of a plurality of materials is formed.

A thin film transistor (TFT) may include an active layer 310, a gate electrode 320, a source electrode 330a, and a drain electrode 330b.

Hereinafter, a case where a thin film transistor (TFT) is a top gate type in which an active layer 310, a gate electrode 320, a source electrode 330a, and a drain electrode 330b are sequentially formed is described. However, this embodiment is not limited to this, and various types of thin film transistors (TFTs) such as a bottom gate type can be used.

The active layer 310 may include a semiconductor substance, such as amorphous silicon or poly crystalline silicon. However, this embodiment is not limited to this, and the active layer 310 may contain various substances. As an alternative embodiment, the active layer 310 may contain an organic semiconductor substance or the like.

As yet another alternative embodiment, the active layer 310 may contain an oxide semiconductor substance. For example, the active layer 310 may include Groups 12, 13, and 14 metal elements selected from, for example, zinc (Zn), indium (In), gallium (Ga), tin (Sn), cadmium (Cd), germanium (Ge), and the like, and Oxides of substances in the combination.

A gate insulating layer 313 is formed on the active layer 310. The gate insulating film 313 functions to insulate the active layer 310 from the gate electrode 320. The film of the gate insulating film 313 including an inorganic substance such as silicon oxide and / or silicon nitride may be formed as a multilayer or a single layer.

The gate electrode 320 is formed to an upper portion of the gate insulating film 313. The gate electrode 320 may be connected to a gate line (not shown) that applies an on / off signal to a thin film transistor (TFT).

The gate electrode 320 may be made of a low-resistance metal substance. The gate electrode 320 may be made of, for example, aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), or magnesium (Mg). ), Gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W ), One or more of copper (Cu) is formed as a single layer or multiple layers.

An interlayer insulating film 315 is formed on the gate electrode 320. The interlayer insulating film 315 insulates the source electrode 330 a and the drain electrode 330 b from the gate electrode 320. A film including an inorganic substance in the interlayer insulating film 315 may be formed as a multilayer or a single layer. For example, the inorganic substance may be a metal oxide or a metal nitride. Specifically, the inorganic substance may include silicon oxide (SiO ₂ ), silicon nitride (SiN _x ), silicon oxynitride (SiON), and aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), or zinc oxide (ZrO ₂ ).

A source electrode 330a and a drain electrode 330b are formed on the interlayer insulating film 315. The source electrode 330a and the drain electrode 330b may be made of aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), One or more of iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and copper (Cu) are formed as a single layer or Multiple layers. The source electrode 330a and the drain electrode 330b are electrically connected to the source region and the drain region of the active layer 310, respectively.

The planarization layer 317 is formed on a thin film transistor (TFT). The planarization layer 317 is formed to cover a thin film transistor (TFT), so that the upper surface can be flattened due to a step difference formed by the thin film transistor (TFT). The film including an organic substance in the planarization layer 317 may be formed as a single layer or multiple layers. Organic substances may include common general polymers such as polymethylmethacrylate (PMMA) or polystylene (PS), polymer derivatives with phenolic groups, acrylic polymers, fluorene Amine polymers, aryl ether polymers, amidine polymers, fluorine polymers, paraxylene polymers, vinyl alcohol polymers and blends thereof. The planarizing layer 317 may be formed of a composite laminate of an inorganic insulating film and an organic insulating film.

A first electrode 510 is positioned on the planarization layer 317. The first electrode 510 may be electrically connected to a thin film transistor (TFT). Specifically, the first electrode 510 may be electrically connected to the drain electrode 330 b through a contact hole formed in the planarization layer 317. The first electrode 510 may have various shapes, for example, may be formed by patterning in an island shape. A barrier layer 400 defining a pixel region may be disposed on the planarization layer 317. The barrier layer 400 may include a recessed portion that receives the micro LED 100. As an example, the barrier layer 400 may include a first barrier layer 410 forming a recessed portion. The height of the first barrier layer 410 may be determined according to the height and viewing angle of the micro LED 100. The size (width) of the recessed portion can be determined according to the resolution, pixel density, and the like of the display device. In one embodiment, the height of the micro LED 100 may be greater than the height of the first barrier layer 410. The recessed portion may have a quadrangular cross-section, but the embodiment of the present invention is not limited thereto, and the cross-section of the recessed portion may have various shapes such as a polygon, a rectangle, a circle, a cone, an oval, and a triangle.

The barrier layer 400 may further include a second barrier layer 420 above the first barrier layer 410. The first barrier layer 410 and the second barrier layer 420 may have a step difference, and a width of the second barrier layer 420 is smaller than a width of the first barrier layer 410. A conductive layer 550 may be disposed on an upper portion of the second barrier layer 420. The conductive layer 550 may be disposed in a direction parallel to the data line or the scan line, and is electrically connected to the second electrode 530. However, the present invention is not limited to this, and the second barrier layer 420 may be omitted and the conductive layer 550 may be disposed on the first barrier layer 410. Alternatively, the second barrier layer 420 and the conductive layer 550 may be omitted, and the second electrode 530 may be formed as a common electrode common to the pixels (P) to the entire display substrate 301. The first barrier layer 410 and the second barrier layer 420 may include a substance that absorbs at least a portion of light, a light reflecting substance, or a light scattering substance. The first barrier layer 410 and the second barrier layer 420 may include an insulating substance that is translucent or opaque with respect to visible light (for example, light in a wavelength range of 380 nm to 750 nm).

As an example, the first barrier layer 410 and the second barrier layer 420 may be made of polycarbonate (PC), polyethylene terephthalate (PET), polyether fluorene, polyvinyl butyral, polyphenylene ether, polyphenylene Thermoplastic resins such as amidine, polyetherimide, norbornene system resin, methacrylic resin, cyclic polyenes, epoxy resin, phenol resin, urethane resin, acrylic resin, vinyl ester The resin, the sulfonyl imide-based resin, the urethane-based resin, the urea resin, the melamine resin, or the like, or an organic insulating material such as polystyrene or polyacrylonitrile is not limited thereto.

As another example, the first barrier layer 410 and the second barrier layer 420 may be made of inorganic insulating materials such as inorganic oxides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , and ZnO _x , and inorganic nitrides. Formation, but it is not limited to this. In one embodiment, the first barrier layer 410 and the second barrier layer 420 may be formed of an opaque material such as a black matrix material. As the insulating black matrix material, organic resins, resins or pastes including glass paste and black pigments, metal particles such as nickel, aluminum, molybdenum and alloys thereof, and metal oxide particles (for example, chromium oxide) can be included. Material), or metal nitride particles (for example, chromium nitride). In a modified example, the first barrier layer 410 and the second barrier layer 420 may be specular reflectors formed of a dispersed Bragg reflector (DBR) having a high reflectance or a metal.

The micro LED 100 is disposed in the recessed portion. The micro LED 100 may be electrically connected to the first electrode 510 in the recessed portion.

The micro LED 100 emits light having wavelengths of red, green, blue, and white, and white light can also be realized by using a fluorescent substance or combining colors. The micro LED 100 has a size of 1 μm to 100 μm. The single or multiple micro LEDs 100 are picked up from the growth substrate 101 and transferred to the display substrate 301 by the micro LED adsorber according to the embodiment of the present invention, thereby being able to be accommodated in the recessed portion of the display substrate 301.

The micro LED 100 includes a p-n diode, a first contact electrode 106 disposed on one side of the p-n diode, and a second contact electrode 107 on the opposite side of the first contact electrode 106. The first contact electrode 106 may be connected to the first electrode 510, and the second contact electrode 107 is connected to the second electrode 530.

The first electrode 510 may be provided with a reflective film formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and a compound thereof, and a transparent or translucent electrode layer formed on the reflective film. The transparent or translucent electrode layer may be selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO, zinc oxide), and indium oxide (In ₂ O ₃₎ . at least one of the groups of indium oxide (IGO), indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

The passivation layer 520 covers the micro LED 100 in the recess. The passivation layer 520 fills a space between the barrier layer 400 and the micro LED 100, thereby covering the recessed portion and the first electrode 510. The passivation layer 520 may be formed of an organic insulating substance. For example, the passivation layer 520 may be formed of acrylic, polymethylmethacrylate (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy resin, polyester, and the like, but is not limited thereto. .

The passivation layer 520 is formed at a height that does not cover the upper portion of the micro LED 100, for example, the second contact electrode 107, so that the second contact electrode 107 is exposed. A second electrode 530 electrically connected to the exposed second contact electrode 107 of the micro LED 100 may be formed on the passivation layer 520.

The second electrode 530 may be disposed on the micro LED 100 and the passivation layer 520. The second electrode 530 may be formed of a transparent conductive material such as ITO, IZO, ZnO, or In ₂ O ₃ .

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 3 (a) and 3 (b).

FIG. 3 (a) is a diagram illustrating a state before the micro LED adsorbent 1000 adsorbs the micro LED 100 according to a preferred embodiment of the present invention, and FIG. 3 (b) is a diagram illustrating a micro LED according to a preferred embodiment of the present invention A diagram of a state where the adsorbent 1000 adsorbs the micro LED 100. The micro LED adsorbent 1000 according to the embodiment of the present invention is a vacuum adsorbent including a porous member 1100 having pores and a mask 1400. The mask 1400 is provided at a lower portion of the porous member 1100 and has an opening 1110. This allows the micro LED 100 to be easily adsorbed to the lower surface of the porous member 1100 by the mask 1400.

A vacuum chamber 1200 is provided above the porous member 1100. The vacuum chamber 1200 is connected to a vacuum port supplying or releasing a vacuum. The vacuum chamber 1200 has a function of applying a vacuum to a plurality of pores of the porous member 1100 or releasing a vacuum applied to the pores by the operation of a vacuum port. The structure in which the vacuum chamber 1200 is coupled to the porous member 1100 is not limited as long as it is a suitable structure that prevents the vacuum from leaking to other parts when a vacuum is applied to the porous member 1100 or the applied vacuum is released.

When the micro LED 100 is vacuum-adsorbed, the vacuum applied to the vacuum chamber 1200 is transmitted to a plurality of pores of the porous member 1100, thereby generating a vacuum adsorption force on the micro LED 100. On the other hand, when the micro LED 100 is desorbed, the vacuum applied to the vacuum chamber 1200 is released, and the plurality of pores of the porous member 1100 are also evacuated, thereby removing the vacuum adsorption force on the micro LED 100.

The porous member 1100 is composed of a substance containing a plurality of pores inside. As a fixed arrangement or a disordered pore structure, the porous member 1100 can be formed into a powder, a thin film / thick film, and a block shape having a porosity of about 0.2 to 0.95. The pores of the porous member 1100 can be divided into micro pores with a diameter of 2 nm or less, meso pores with a diameter of 2 nm to 50 nm, and macro pores with a diameter of 50 nm or more, including these pores. At least a part of. The porous member 1100 can be classified into organic, inorganic (ceramic), metal, and hybrid porous raw materials according to its constituent components. The porous member 1100 includes an anodized film in which pores are formed in a fixed arrangement. The shape of the porous member 1100 can be powder, coating film, or block. In the case of a powder, the porous member 1100 can have various shapes such as a spherical shape, a hollow spherical shape, a fiber, and a tube shape. Although the powder is directly used, it may be This can be used as a starting material to produce a coating film or a block shape.

When the pores of the porous member 1100 have a disordered pore structure, a plurality of pores are connected to each other inside the porous member 1100 to form an air flow path connecting the upper and lower portions of the porous member 1100. On the other hand, when the pores of the porous member 1100 have a vertical pore structure, the inside of the porous member 1100 can penetrate the upper and lower sides of the porous member 1100 through the vertical pores to form an air flow path.

A mask 1400 is provided below the porous member 1100. The mask has an opening 1110, and a non-adsorption region 1130 is formed on a surface on which the opening 1110 is not formed.

As shown in FIG. 4, the mask 1400 is formed with an opening portion 1110, and a non-adsorption region 1130 is formed on a surface on which the opening portion 1110 is not formed.

When the pitch in the column direction of the microLEDs 100 on the growth substrate 101 is P (n) and the pitch in the row direction is P (m), the openings 1110 may be formed at the same pitch as the pitch of the microLEDs 100 on the growth substrate 101. In other words, when the column-direction pitch of the micro LEDs 100 on the growth substrate 101 is P (n) and the row-direction pitch is P (m), the column-direction pitch of the openings 1110 of the mask 1400 is P (n), The pitch in the row direction is P (m). Due to the structure described above, the micro LED adsorbent 1000 provided with the mask 1400 under the porous member 1100 can vacuum-adsorb all the micro LEDs 100 on the growth substrate 101 and transfer them.

The area of the opening portion 1110 may be formed to be larger than the horizontal area of the upper surface of the micro LED 100. In other words, the diameter D of the opening portion 1110 may be formed to be larger than the horizontal length of the upper surface of the micro LED 100. In a case where the area of the opening portion 1110 is formed to be larger than the horizontal area of the upper surface of the micro LED 100, the present invention can be implemented as the embodiment shown in FIGS. 3 (a) and 3 (b).

As shown in FIGS. 3 (a) and 3 (b), the mask 1400 is provided under the porous member 1100. The mask 1400 is provided by being adsorbed to the porous member 1100 by a vacuum suction force of the porous member 1100.

FIG. 3 (a) is a diagram illustrating a state before the micro LED absorber 1000 is equipped with a mask 1400 having an opening 1110 having an area larger than a horizontal area of an upper surface of the micro LED 100 before the micro LED 100 is adsorbed. As shown in FIG. 3 (a), the lower surface of the porous member 1100 has a shape in which a non-adsorption region 1130 and an opening 1110 are formed by the mask 1400.

The non-adsorption region 1130 of the mask 1400 is a region formed by the mask 1400 having the opening portion 1110, and therefore has the same thickness as the mask 1400, and thus can form a step with the opening portion 1110.

The non-adsorption region 1130 of the mask 1400 has a function of blocking the pores on the lower surface of the porous member 1100, and thus functions as a shielding portion in the porous member 1100. Therefore, the vacuum pressure formed by transmitting the vacuum of the vacuum chamber 1200 to the porous member 1100 can be made larger by the opening portion 1110 of the mask 1400. The micro LED 100 can be efficiently adsorbed to the lower surface of the porous member 1100 by forming the opening 1110 having a large vacuum pressure.

FIG. 3 (b) is a diagram showing a state in which the micro LED 100 is adsorbed by the micro LED adsorber 1000 equipped with the mask 1400 having the opening portion 1110 having an area larger than the horizontal area of the upper surface of the micro LED 100. As shown in FIG. 3 (b), in the micro LED adsorbent 1000, the non-adsorption region 1130 of the mask 1400 provided at the lower portion of the porous member 1100 functions as a shielding portion and blocks a part of the surface of the lower portion of the porous member 1100. Therefore, the opening portion 1110 forming a large vacuum pressure is formed to adsorb the micro LED 100 in an adsorption area and vacuum adsorb the micro LED 100.

If the lower part of the porous member 1100 is provided with a mask 1400 having an opening portion 1110 having a size larger than the horizontal area of the upper surface of the micro LED 100 as in FIGS. 3 (a) and 3 (b), The opening 1110 directly contacts the micro LED 100 with the lower surface of the porous member 1100 having a uniform flatness and vacuum-adsorbs the micro-LED 100. Therefore, the micro-LED 100 can be prevented from falling off during vacuum adsorption.

This situation can be achieved by the vacuum pressure of the porous member 1100 formed by transmitting the vacuum from the vacuum chamber 1200 to the opening 1110 of the mask 1400, and the micro LED 100 can be more fully vacuumed. The function of adsorbing the lower surface of the porous member 1100 with uniform flatness.

In addition, when the micro LED adsorbent 1000 is provided with the mask 1400 having an opening 1110 having an area larger than the horizontal area of the upper surface of the micro LED 100, the micro LED adsorbent 1000 may not cause the micro LED 100 to generate an upper portion of the micro LED 100. The micro LED 100 is easily vacuum-adsorbed due to damage caused by a collision between the outside of the surface and the stepped portion of the non-adsorption region 1130 of the mask 1400.

The mask 1400 is provided by changing the pitch in the column direction and the pitch in the row direction.

5 to 7 are diagrams illustrating an embodiment in which the pitch in the column direction or the pitch in the row direction of the mask 1400 according to the embodiment of the present invention is changed.

As shown in FIG. 5, when the pitch of the micro LEDs 100 of the mask 1400 on the growth substrate 101 is P (n) and the pitch of the row direction is P (m), the pitch of the openings 1110 in the column direction may be 3P (n ), The spacing in the row direction is P (m). Here, 3P (n) means three times the column direction pitch P (n) shown in FIG. 4. According to the configuration described above, only the micro LEDs 100 corresponding to three times the rows can be vacuum-adsorbed and transferred. Here, the micro LEDs 100 transmitted in three-fold columns may be any one of a red LED, a green LED, a blue LED, and a white LED. According to the configuration described above, the micro LEDs 100 of the same light emission color mounted on the display substrate 301 can be shifted at intervals of 3P (n).

As shown in FIG. 6, when the column direction pitch of the micro LEDs 100 on the growth substrate 101 of the mask 1400 is P (n) and the row direction pitch is P (m), the column direction pitch of the openings 1110 may be P (n ), The spacing in the row direction is 3P (m). Here, 3P (m) means 3 times the pitch P (m) in the row direction shown in FIG. 4. According to the configuration described above, only the micro LEDs 100 corresponding to three times the rows can be vacuum-sucked and transferred. Here, the micro LEDs 100 transmitted in three-fold rows may be any one of a red LED, a green LED, a blue LED, and a white LED. According to the configuration described above, the micro LEDs 100 of the same light emission color mounted on the display substrate 301 can be shifted at intervals of 3 P (m).

As shown in FIG. 7, when the pitch of the micro LEDs 100 of the mask 1400 on the growth substrate 101 is P (n) and the pitch of the row direction is P (m), the openings 1110 may be formed in a diagonal direction. The pitches in the direction and the row direction are formed as 3P (n) and 3P (m), respectively. Here, the micro LEDs 100 transmitted in three times the rows and three times the columns may be any one of a red LED, a green LED, a blue LED, and a white LED. According to the configuration as described above, the micro LEDs 100 of the same light emission color mounted on the display substrate 301 are spaced apart at a pitch of 3P (n) and 3P (m), so that the micro LEDs 100 of the same light emission color can be transferred in a diagonal direction.

The mask 1400 can be formed of various materials such as nickel steel (invar) material, anodized film, metal material, film material, paper material, and the like.

The low thermal expansion coefficient of the nickel steel material prevents interface deformation due to thermal effects. In addition, similar to porous ceramics, the anodic oxide film also has the characteristics of being less affected by heat. Therefore, when the mask 1400 is formed of a nickel steel material or an anodized film material, it has the ability to prevent the interface caused by thermal effects. Deformation problem effect.

The mask 1400 may be formed of a metal material and provided. Since the metal material is easy to process, the opening 1110 of the mask 1400 can be easily formed. Therefore, when the shield 1400 is formed of a metal material, there is an effect that manufacturing convenience can be improved.

In addition, when the mask 1400 is made of a metal material, when a metal bonding method is used as a method for bonding the micro LED 100 to the first contact electrode 106 of the display substrate 301, no power is applied to the display substrate 301, and the micro LED is used. The mask 1400 of the adsorbent 1000 heats the upper surface of the micro LED 100 and heat-bonds a metal (alloy), so that the micro LED 100 can be bonded to the first contact electrode 106.

The mask 1400 can be made of a film material. When the micro LED adsorbent 1000 equipped with the mask 1400 adsorbs the micro LED 100, foreign matter adheres to the surface of the mask 1400. The mask 1400 can be cleaned and reused, but there is a problem that the mask 1400 is complicated to clean each time. Therefore, when the mask 1400 is provided with a film material, when the foreign matter is attached, the mask 1400 itself can be removed and easily replaced for convenient use. The mask 1400 can be made of a paper material. When a foreign matter is adhered to the surface of the mask 1400 made of a paper material, the mask 1400 can be easily replaced without removing the cleaning process separately, and thus can be used conveniently.

The mask 1400 can be made of an elastic material in addition to a nickel steel material, an anodized film, a metal material, a film material, or a paper material.

When the mask 1400 is formed of an elastic material, it can provide a cushioning effect to prevent the micro LED 100 from being damaged. For example, it is adjusted so that the upper surface of the micro LED adsorbent 1000 and the micro LED 100 only has a pitch of several μm to several tens μm and falls. However, when the micro LED adsorbent 1000 is lowered to adsorb the micro LED 100, it is difficult to finely adjust the lowered position. The reason is that, due to the mechanical tolerance of the micro LED adsorbent 1000, even if the micro LED adsorber 1000 is adjusted in such a manner as to keep a distance of several μm to several tens μm from the upper surface of the micro LED 100 to decrease, it will be more difficult due to the tolerance range. The lowered position of the adjusted micro LED adsorbent 1000 is further lowered.

When the micro LED adsorbent 1000 is lower than the adjusted lowering position, a problem occurs that the micro LED 100 is damaged due to collision with the upper surface of the micro LED 100. However, when the cover 1400 provided in the micro LED adsorbent 1000 is an elastic material, the conveyance error in the downward direction of the micro LED absorber 1000 can be accommodated by the mask 1400, and therefore, it can play a buffering role.

The mask 1400 can be provided to the micro LED adsorbent 1000 by changing the shape and area size of the opening portion 1110.

FIGS. 8 and 9 illustrate modified examples of the micro LED adsorbent 1000 shown in FIGS. 3 (a) and 3 (b). The micro LED adsorbent 1000 shown in FIG. 8 is provided with a mask 1400 having an area and an opening size 1110 which are different from those of the mask 1400 shown in FIG. 4 in a lower portion of the porous member 1100. As shown in FIG. 8, the micro LED adsorbent 1000 is provided with a cover 1400 having an opening portion 1110 having an area smaller than the horizontal area of the upper surface of the micro LED 100 in the lower portion of the porous member 1100. The area of the opening portion 1110 of the mask 1400 is smaller than the horizontal area of the upper surface of the micro LED 100. In other words, the lower surface of the porous member 1100 is provided with a mask 1400 having an opening portion 1110 with a diameter D smaller than the horizontal length of the upper surface of the micro LED 100. The micro LED adsorbent 1000 shown in FIG. 8 can increase the vacuum adsorption area of the micro LED 100 by the configuration of the mask 1400 having the opening portion 1110 having an area smaller than the horizontal area of the upper surface of the micro LED 100.

The micro LED adsorbent 1000 shown in FIG. 9 is provided with a mask 1400 having the same area as the mask 1400 shown in FIG. 4 in the lower portion of the porous member 1100, and the mask 1400 having a different shape of the mask 1110. As shown in FIG. 9, the micro LED adsorbent 1000 is provided with a mask 1400 below the porous member 1100. The inside of the opening 1110 of the mask 1400 on the direct contact surface side that is in direct contact with the lower surface of the porous member 1100 is as follows. The diameter is formed to be larger than the horizontal area of the upper surface of the micro LED 100, and the inner diameter is formed to be larger than the inner diameter of the opening portion 1110 on the direct contact surface side as the upper surface side of the micro LED 100 is oriented. . The micro LED adsorbent 1000 shown in FIG. 9 is provided with a mask 1400 having an opening portion 1110 whose inner diameter becomes smaller as it faces the direct contact surface side which is in direct contact with the lower surface of the porous member 1100. The inner side surface of the opening is formed obliquely, and the minimum inner diameter of the opening 1110 is formed to be larger than the horizontal area of the upper surface of the micro LED 100. The micro LED adsorbent 1000 is configured to be equipped with the above-mentioned mask 1400. When the micro LED 100 is vacuum-adsorbed, the micro LED 100 can be guided to the micro LED and the porous member 1100 can be vacuum-adsorbed. The vacuum suction position of the lower surface of the micro LED 100 can accurately vacuum-vacuate to the exact position.

FIGS. 10 (a) to 10 (e) are diagrams illustrating a method of transferring the micro LED 100 by using the micro LED adsorbent 1000 according to the embodiment of the present invention in which the mask 1400 of FIG. 4 is provided under the porous member 1100. In FIG. 10, the mask 1400 shown in FIG. 4 is provided, but the mask 1400 shown in FIGS. 5 to 9 may be provided.

As shown in FIG. 10 (a), the porous member 1100 that transmits the vacuum applied to the vacuum chamber 1200 to a plurality of air holes and generates a vacuum suction force absorbs the mask 1400 with the vacuum suction force. As shown in FIG. 10 (b), the mask 1400 is provided by being adsorbed to the porous member 1100 by a vacuum suction force. As shown in FIG. 10 (c), the plurality of micro LEDs 100 formed on the growth substrate 101 are brought into a state where they can be separated from the growth substrate 101. After that, after the micro LED adsorbent 1000 is moved to the upper portion of the growth substrate 101 to be positioned, the micro LED adsorbent 1000 is lowered. The micro LED adsorbent 1000 applies vacuum to the porous member 1100 by forming a vacuum pressure through the vacuum port, and vacuum adsorbs the micro LED 100 as shown in FIG. 10 (d). When the micro LED adsorbent 1000 adsorbs the micro LED 100 with a vacuum force, the porous member 1100 of the micro LED adsorbent 1000 can be brought into close contact with the micro LED 100 to perform vacuum adsorption. After that, the micro LED adsorbent 1000 is moved to the upper portion of the display substrate 301 to be positioned and lowered. At this time, although not shown in the figure, the mask 1400 and the micro LEDs 100 that adsorb the vacuum on the lower portion of the porous member 1100 and release the vacuum applied to the porous member 1100 through the vacuum port can be transferred to the display substrate 301. Thereafter, the micro LEDs 100 transmitted on the display substrate 301 may be bonded to the first contact electrode 106 of the display substrate 301 by applying power to the display substrate 301. Thereafter, as shown in FIG. 10 (e), the micro LED adsorbent 1000 is formed with a vacuum pressure by the vacuum port, so that a vacuum can be applied to the porous member 1100 and the mask 1400 transferred to the display substrate 301 can be adsorbed again. Since the micro LED 100 is bonded to the first contact electrode 106, only the mask 1400 can be vacuum-adsorbed to the lower portion of the porous member 1100. In the present invention, it is shown that the micro LED adsorbent 1000 once again removes the mask 1400 transferred to the display substrate 301, but the mask 1400 can be removed by other appropriate methods.

In addition, although not shown, as shown in FIG. 10 (d), the micro LED adsorbent 1000 that vacuum-adsorbs the micro LED 100 can be moved to the upper portion of the display substrate 301 and positioned after descending. The lowered micro LED adsorbent 1000 can bond the micro LED 100 by heating the upper surface of the micro LED 100 with a mask 1400 in a state where the micro LED 100 is pressed by the upper surface of the micro LED 100 adsorbed by vacuum. After the micro LED 100 is bonded, the micro LED adsorber 1000 can be raised in a state where the mask 1400 is vacuum-adsorbed on the lower part of the porous member 1100 like FIG. 10 (e), and the micro LED 100 can be transferred to the display substrate 301 only.

As described above, the micro-LED adsorbent 1000 of the present invention is provided with the cover 1400, and the vacuum pressure of the micro-LED 100 can be formed by the opening 1110 of the cover 1400. The micro-LED 100 directly and The lower surface of the porous member 1100 having a uniform flatness is in contact with each other, so that it can be prevented from falling off during vacuum adsorption.

As described above, the description has been made with reference to the preferred embodiments of the present invention, but a person of ordinary skill in the art can make the present invention without departing from the spirit and field of the present invention described in the scope of the attached patent application. Various corrections or deformations are performed.

100‧‧‧Micro LED

101‧‧‧Growth substrate

102‧‧‧First semiconductor layer

103, 310‧‧‧ Active layer

104‧‧‧Second semiconductor layer

106‧‧‧First contact electrode

107‧‧‧Second contact electrode

301‧‧‧display board

311‧‧‧Buffer layer

313‧‧‧Gate insulation film

315‧‧‧Interlayer insulation film

317‧‧‧ flattening layer

320‧‧‧ Gate electrode

330a‧‧‧Source electrode

330b‧‧‧Drain electrode

400‧‧‧ barrier wall

410‧‧‧The first barrier layer

420‧‧‧Second barrier layer

510‧‧‧first electrode

520‧‧‧ passivation layer

530‧‧‧Second electrode

550‧‧‧ conductive layer

1000‧‧‧Micro LED adsorbent

1100‧‧‧ porous parts

1110‧‧‧ opening

1130‧‧‧ non-adsorption area

1200‧‧‧Vacuum chamber

1400‧‧‧Mask

D‧‧‧ diameter

P‧‧‧Pitch

S‧‧‧ separated distance

W‧‧‧Width

FIG. 1 is a diagram illustrating a micro LED that is a transmission target according to an embodiment of the present invention.

FIG. 2 is a diagram showing a micro LED structure mounted by being transferred to a display substrate according to an embodiment of the present invention.

FIG. 3 (a) is a diagram illustrating a state before a micro LED adsorbent adsorbs a micro LED according to a preferred embodiment of the present invention.

FIG. 3 (b) is a diagram illustrating a state in which a micro LED adsorbent adsorbs a micro LED according to a preferred embodiment of the present invention.

4 to 7 are diagrams illustrating an embodiment of a mask according to an embodiment of the present invention.

FIG. 8 is a diagram illustrating a first modified example of the embodiment of the present invention.

FIG. 9 is a diagram illustrating a second modification of the embodiment of the present invention.

FIG. 10 is a diagram illustrating a method for transferring a micro LED using a micro LED adsorbent according to an embodiment of the present invention.

Claims (6)

A microluminescent diode adsorbent, which is characterized by being equipped with: Porous parts with pores; and The mask is provided to a lower portion of the porous member and has an opening portion. The microluminescent diode adsorbent according to item 1 of the scope of patent application, characterized in that: The mask is made of nickel steel. The microluminescent diode adsorbent according to item 1 of the scope of patent application, characterized in that: The mask is made of metal. The microluminescent diode adsorbent according to item 1 of the scope of patent application, characterized in that: The mask is made of a film material. The microluminescent diode adsorbent according to item 1 of the scope of patent application, characterized in that: The mask is made of paper. The microluminescent diode adsorbent according to item 1 of the scope of patent application, characterized in that: The mask is provided by being adsorbed to the porous member by a vacuum suction force of the porous member.